U.S. Pat. No. 6,572,698 to Ko discloses an activated aluminosilicate composition containing aluminosilicates, calcium sulphate and an activator containing alkali metal salts is disclosed. The aluminosilicates are selected from a group consisting of blast furnace slag, clay, marl and industrial by-products, such as fly ash, and has an Al2O3 content greater than 5% by weight. Blast furnace slag is present in an amount less than 35% by weight, and cement kiln dust (CKD), in an amount of from 1 to 20% by weight, is added to the mixture as an activator.
U.S. Pat. No. 4,488,909 to Galer et al discusses cementitious compositions capable of rapid setting. The cementitious composition includes portland cement, high alumina cement, calcium sulfate and lime. Pozzolans such as fly ash, montmorillonite clay, diatomaceous earth and pumicite may be added up to about 25%. The cement composition includes about 14 to 21 wt % high alumina cement. Galer et al provided aluminates using high alumina cement (HAC) and sulfate ions using gypsum to form ettringite and achieve rapid setting of their cementitious mixture.
U.S. Pat. No. 6,869,474 to Perez-Pena et al, discusses cementitious compositions for producing cement-based products such as cement boards. This is achieved by adding an alkanolamine to hydraulic cement such as portland cement, and forming a slurry with water under conditions that provide an initial slurry temperature of at least 90° F. (32° C.). Additional reactive materials may be included such as high alumina cement, calcium sulfate and a pozzolanic material such as fly ash.
U.S. Pat. No. 7,670,427 of Perez-Pena et al, discusses cementitious compositions with early-age compressive strength for producing cement-based products such as cement boards achieved by adding an alkanolamine and a phosphate to hydraulic cement such as portland cement, and forming a slurry with water under conditions that provide an initial slurry temperature of at least 90° F. (32° C.). Additional reactive materials may be included such as high alumina cement, calcium sulfate and a pozzolanic material such as fly ash.
US published patent application No. US 2010-0071597 A1 of Perez-Pena discloses formulations using fly ash and alkali metal salts of citric acid such as sodium citrate to form concrete mixes with fast setting time and relatively high early age compressive strength. Hydrolaulic cement and gypsum can be used up to 25 wt % of the formulation, although their use is not preferred. The activated fly ash compositions described in this application may interact with the traditional foaming systems used to entrain air and thereby make lightweight boards.
U.S. Pat. No. 5,536,310 to Brook et al disclose a cementitious composition containing 10-30 parts by weight (pbw) of a hydraulic cement such as portland cement, 50-80 pbw fly ash, and 0.5-8.0 pbw expressed as a free acid of a carboxylic acid such as citric acid or alkali metal salts thereof, e.g., tripotassium citrate or trisodium citrate, with other conventional additives, including retarder additives such as boric acid or borax.
U.S. Pat. No. 6,641,658 to Dubey discloses a Portland cement based cementitious composition which contains 35-90% Portland cement, 0-55% of a pozzolan, 5-15% of high alumina cement and 1 to 8% of insoluble anhydrite form of calcium sulfate in place of the soluble conventional landplaster/gypsum to increase the release of heat and decrease setting time despite the use of high amounts of pozzolan, e.g., fly ash. The cementitious composition can include lightweight aggregates and fillers, superplasticizers and additives such as sodium citrate.
U.S. Pat. No. 7,618,490 B2 to Nakashima et al. discloses a quick setting spraying material comprising one or more of calcium sulfoaluminate, calcium aluminosilicate, calcium hydroxide, a source of fluorine and Portland cement concrete. Calcium sulfate may be added as anhydrous or as a hemihydrate.
U.S. Pat. No. 4,655,979 to Nakano et al. discloses a process for making a cellular concrete using calcium silicate based cement, alkali metal retarder, calcium sulfo-aluminate (CSA) cement and an optional calcium sulfate that can be added to the concrete composition.
US 2008/0134943 A1 to Godfrey et al. discloses a waste encapsulation material composed of at least one sulphoaluminate salt of an alkaline earth metal with calcium sulphate, and optional inorganic filler such as blast furnace slag, pulverized fuel ash, finely divided silica, limestone, and organic and inorganic fluidizing agents. Preferably at least one sulphoaluminate salt of an alkaline earth metal comprises calcium sulphoaluminate (CSA). A suitable composition may, for example, comprise at least one sulphoaluminate salt of an alkaline earth metal in combination with gypsum and pulverized fuel ash (PFA), wherein about 86% of the gypsum particles have a particle size of less than 76 um, and roughly 88% of the PFA particles have a particle size below 45 um. One example comprises 75% (70:30CSA:CaSO4.2H2O), 25% Pulverized Fuel Ash; water/solids ratio 0.65.
U.S. Pat. No. 6,730,162 to Li et al. discloses dual cementitious compositions including a first hydraulic binder having 2.5% to 95 wt. % C4A3S which is chemical notation wherein C═CaO, S═SiO2, A=Al2O3 (in other words calcium sulfo-alumina) and 2.5 to 95 wt. % a hemihydrate and/or an anhydrite of calcium sulfate. Sulfoalumina cements or ferroalumina cements are examples of cements that contain C4A3S. It may also include mineral filler additives selected from the group consisting of slag, fly ash, pozzolan, silica soot, limestone fines, lime industrial by-products and wastes.
Chinese published application CN 101921548 A to Deng et al. discloses a composition of sulfoaluminate cement made from 90-95 wt % sulfoaluminate clinker and anhydrous gypsum, quartz sand, fly ash from waste incineration, hydroxypropyl methylcellulose ether, redispersible glue powder and fiber. The sulfoaluminate clinker and anhydrous gypsum meets the standard of sulfoaluminate cement, i.e. GB20472-2006.
Korean published application KR 549958 B1 to Jung et al. discloses a composition of alumina cement, CSA, gypsum, calcium citrate, and hydroxyl carboxylic acid.
Korean published application KR 2009085451 A to Noh, discloses a composition of powdered blast furnace slag, gypsum and CSA. The gypsum can have an average particle size of 4 micron or less.
KR 2009025683 A discloses powder type waterproof material used for concrete and mortar, is obtained by pulverizing cement, anhydrous gypsum, silica powder, waterproof powder, fly ash, calcium sulfoaluminate type expansion material and inorganic compostion.
Korean published application KR 2010129104 A to Gyu et al. discloses composition for blending shotcrete, comprises (in wt. %): metakaolin (5-20), calcium sulfoaluminate (5-20), anhydrous gypsum (20-45), and fly ash (30-50).
There is a need for a dimensionally stable fly ash based geopolymeric compositions and method to reduce the amount of shrinkage, initial and final temperature behavior and reduce seting time of fly ash based compositions mixes so these formulations can be used to manufacture cementitious concrete products with improved strength.